Addressing water scarcity in the Bolivian Altiplano for sustainable water management

Abstract: Water scarcity is a consequence of complex interactions between water access and water use. In fact, the time period over which precipitation deficit accumulates is a determing factor for the occurrence of drought. Drought induces crop production losses and far-reaching societal effects. In the South American Altiplano, drought is a major hazard. Here, drought leads to food shortages, malnutrition, migration, loss of biodiversity, and local conflicts. In order to improve the drought resilience and develop mitigation and adaptation strategies, there is a need to study water scarcity episodes, and their drivers in the Bolivian Altiplano. Therefore, the main goal of this study was to address the Bolivian Altiplano water scarcity for sustainable water management. In the first instance, previous research on the subject was synthetized in a state of art with respect to climate and water resources. Secondly, analysis of precipitation variability, and its relation with climate phenomena were performed. It involved the analysis of the long-term austral summer precipitation variance at six locations in the Bolivian Altiplano. The precipitation variability was related to climate anomalies over the Pacific and Atlantic Ocean. The results show significant negative relationship between summer precipitation and climate phenomena in the studied region. Thirdly, a hydrological study to define the soil moisture characteristics was initiated in a river basin of the Bolivian Altiplano. It involved soil moisture estimations using soil water balance and satellite derived approaches. The estimated soil moisture was compared and validated with gauged soil moisture. The soil moisture estimations were used to define the impact of water scarcity in agricultural production. Finally, a drought risk analysis based on the association of precipitation and temperature variability with quinoa and potato yield was accomplished. For this, montlhy satellite data of precipitation and temperature were validated with gauged data. The precipitation and temperature were related to agricultural production in the studied region. The normalized difference vegetation index was used to estimate the crop yield of the agricultural area. It was found that the variance of the agricultural production depends largely on the precipitation and temperature variance. The findings of this thesis provide insights in identifying strategies to improve the water management in the Bolivian Altiplano, mainly during water stress conditions. Moreover, the analyses enhance the knowledge for seasonal forecasting, drought disaster risk management, proactive planning, and mitigation policy measures in vulnerable regions of the Bolivian Altiplano.